In an interview with Ezra Klein of the Washington Post yesterday, former vice president Al Gore said that global warming is causing more extreme weather – so much more, in fact, that the hurricane scale would soon, Spinal Tap-like, include six categories instead of just five.
However, according to Chris Vaccaro, director of public affairs at the National Weather Service, that’s not the case.
Vaccaro told me that the possibility of adding a sixth category to the Saffir-Simpson Hurricane Wind Scale ratings, the well known system that ranges from Category 1 to 5, has been raised in the past, but, contra Gore, there are currently no plans to do so.
Moreover, categories are defined solely on wind speed; Category 5 hurricanes, the class with the highest wind speeds, are hurricanes with winds measured at or above 157 miles per hour (I neglected to ask if Gore’s bluster has been known to qualify). In other words, Category 5 currently includes anything that could possibly be considered part of a sixth theoretical category. There has not been a Category 5 hurricane in the Atlantic Ocean since 2007.